Apply a Function over a Ragged Array in R Programming – tapply() Function Improve Improve Like Article Like Save Share Report tapply() function in R Language is used to apply a function over a subset of vectors given by a combination of factors Syntax: tapply(vector, factor, fun) Parameters: vector: Created Vector factor: Created Factor fun: Function to be applied Example 1: # R Program to apply a function # over a data object # Creating Factor fac <- c(1, 1, 1, 1, 2, 2, 2, 3, 3) # Created Vector vec <- c(1, 2, 3, 4, 5, 6, 7, 8, 9) # Calling tapply() Function tapply(vec, fac, sum) Output: 1 2 3 10 18 17 This is how above code works: Example 2: # R Program to apply a function # over a data object # Creating Factor fac <- c(1, 1, 1, 1, 2, 2, 2, 3, 3) # Created Vector vec <- c(1, 2, 3, 4, 5, 6, 7, 8, 9) # Calling tapply() Function tapply(vec, fac, prod) Output: 1 2 3 24 210 72 Last Updated : 19 Jun, 2020 Like Article Save Article Previous Check if a Factor is an Ordered Factor in R Programming - is.ordered() Function Next Applying a Function over an Object in R Programming - sapply() Function Share your thoughts in the comments Add Your Comment Please Login to comment...